The present invention relates generally to heart assist pumps, and, more specifically, to control thereof in cooperation with the natural heart.
One form of heart dysfunction is the inability for the left ventricle to sufficiently pump blood over various levels of patient activity. Heart assist pumps have been undergoing development for many years for supplementing the pumping capability of the dysfunctional heart.
Since the heart is a muscle which pumps blood in periodic pulses in each heartbeat cycle, the heart assist pump must be capable of complementing natural heart flow without adversely affecting natural performance of the heart.
Many forms of heart assist pumps have undergone development, with different advantages and disadvantages. One form of heart assist pump made in small, implantable size is the Left Ventricular Assist Device (LVAD) which is sutured in flow communication between the left ventricle and the aorta. The LVAD operates in parallel flow with the left ventricle for collectively pumping the blood through the aorta for feeding the arterial branch.
The various heart assist pumps undergoing development have various sizes and configurations from large to small and from rotary to reciprocating. And, each of these pumps must be suitably controlled for pumping blood in conjunction with the left ventricle.
Recently, there have been significant advances in the development of heart assist pumps. Second and third generation rotary pumps are smaller and lighter and have demonstrated viability for long-term support. These pumps are being designed to be totally implantable and to enable patients to eventually leave the hospital and resume normal activities. These new generations of rotary pumps cannot rely on the simple passive fill mechanism that provided physiological control for the first generation of pulsatile heart pumps.
Since the left ventricle undergoes a diastolic filling cycle and systolic pumping cycle, the heart assist pump must be suitably controlled in conjunction with the pulsatile pumping of the natural heart.
Accordingly, it is desired to provide an improved heart assist pump and control system for supplementing blood pumping of the natural heart in situ.
A blood pump is joined in parallel flow between the left ventricle and aorta of a patient""s heart. The pump includes an inlet pressure sensor and cooperating controller for measuring inlet pressure to the pump to control operation thereof. The controller adjusts speed of the pump in a closed loop control using feedback of the measured inlet pressure to conform operation of the pump with the natural cycle of the heart.